PROTONATION CONSTANTS OF 2,6-BIS(2-PYRIDYL)PYRIDINE AND 2,4,6-TRIS(2-PYRIDYL)-1,3,5-TRIAZINE AND FORMATION CONSTANTS OF THEIR BINARY AND TERNARY IRON(II) COMPLEXES

Abstract

Equilibrium constants involving the ternary mixed ligand iron(II) complex [Fe(TPTZ)(terpy)]²⁺, determined spectrophotometrically at 23° and μ=0.5 M, are reported. Acidity constants of the protonated ligands and formation constants of the binary iron(II) complexes [Fe(TPTZ)₂]²⁺ and [Fe(terpy)₂]²⁺, measured as an adjunct to determining the ternary complex constants, are also reported. The results are of interest in elucidating mixed-ligand complexation effects as well as in confirming or correcting previously reported equilibrium constants of the binary complexes.